Hi, presupuestON.
I have just fixed a similar problem of concatenating two complete paths. At me it was created in a plugin lj-xp transfer in function “load_plugin_textdomain” the third parameter $plugin_rel_path of a full path instead of relative from a folder /wp-content/plugins/. I commented out the wrong line and wrote the correct.
//load_plugin_textdomain( 'lj-xp', false, plugin_dir_path(__FILE__) . '/lang' );
load_plugin_textdomain( 'lj-xp', false, 'lj-xp/lang' );
Backslashes don’t mean a thing in this issue.
